Abrasive wheel



Nov. 20, 1928. 1,692,329

- G. O. BU RLEW ABRASIVE WHEEL Filed Sept. 10, 1927 5 INVENTOR.

- qw?D A TTORNEY Patented Nov. 20,1928.

UNITED STATES PATENT OFFICE.

GILIDEROY O. BURLEW, OF NEWARK, NEW JERSEY.

ABRASIVE WHEEL.

Application filed September 10, 1927. Serial No. 218,695.

This invention relates to abrasive wheels and more particularly to types of a fine character and small size, as used by dentists.

Such wheels are usually composed of grinding materials united by rubber or cement whereby the particles-of the abrasive are held in a coherent mass,.shaped by moulding into a disc-like form.

It is well-known that rubber, in the presence of moisture and upon wet surfaces, has

a slipping or sliding action over such sur-- faceds without the clinging efiect'which is desire It has been proposed therefore to unite with the ingredients of the wheel, a substance that is measurably elastic and has a gripping or clinging tendency, such for instance as cork, but whilekcork has certain desirable characteristics, it also has others which render its employment unsatisfactory, such as ready separation from its matrix, crumbling and utter lack of absorption, being repellent to liquids.

In the present construction another substance, namely sponge, is used with a satis-- factory result, and it is therefore one of the objects of the present invention to provide an abrasive wheel in which a large ercentage of sponge is used, its fragments lieing vulcanized with the rubber and having incorporated therein any preferred abrading-mate rial, as pumice stone, which clings to the sponge, while the sponge has a pronounced wiping effect. 7 4

A further feature is in the provision of a wheel which is tougher and more yielding, and less inclined to become slippery in the presence of moisture, which in itself is highly absorbent, and unites well with any suitable .7

abradents so as to provide a grinding wheel having excellent cutting properties and at a moderate expense.

These objects are attained by the novel selection of materials and combination thereof as hereinafter described and shown in the accompanying drawing, in which Figure 1 is a side view of an abrasive wheel] made in accordance with the invention.

Figure 2 is a partial edge and transverse sectional view of the same.

As is well known sponge is an animal substance having a porous body'which, after the removal of the living matter, constitutes a skeleton or network of elastic fibers composed of spicuate members raised and integrally connected forming flagellated chambers, the

walls of which are composed of a soft hornlike. substance with a certain amount of silica.

The sponge is comminuted or cut into small fragments,such for instance as would pass through a screen of say 20 to the inch, and in this condition is commingled with the abrasive material together with pure Para rubber gum disposed in moulds of the desired shape.

Suflicient heat is applied to cause the rubber to vulcanize,'filling the interstices of the sponge and retaining the finely divided cutting substance therein.

It is further found in practice that vthe sponge acts as an absorbent to retain moisture rendering the cutting action of the wheel cool, cleanly, and comfortable,'the result being that substantially no residue is left in the mouth of the partv undergoing treatment.

It is further found that the fragments of the sponge unite with rubber forming a highly satisfactory base in which the cutting particles are imbedded and tend to prevent the tearing out or breaking away of minute portions of the wheel, such as occurs in any known combination of wheel substances to a far greater extent than in that herein disclosed.

Such wheels do not glaze, neither do they glide over the work surface uselessly, but present an elastic fibrous body which upon being magnified discloses a fuzzy surface, due to the peculiar natural structure of the sponge, held by the bonding effect of the rubber and constituting an effective matrix for the cutting particles with which the mass is impregnated, such as emery, carborundum, etc.

Any desired abrasive may be used in a variety of degrees of fineness according to the work to be done.

The size of the sponge fragments may also vary and the binder used in incorporating the mass is selective in view of its purpose. In

practice the sponge, designated by the nu meral 5, may constitute from ten to forty per cent of the bulk of the wheel, therubber 6, fifteen to fifty percent and the abrasive 7, thirty to forty percent.

Moulding and vulcanizing are conducted in the usual manner to produce awheel 8 having an axial opening 9-to receive a driving spindle by which it may beoperated- Although the foregoing -constitutes the best known manner of construction and embodi ment of the invention, it isnot desired to be confined to the exact composition, specific ingredients, size and proportions, or manner of of rubber vulcanized with the abrasive andconstruction, except as limited by the apsponge. pended claims. 3. A grinding wheel comprising an abra- Having thus described my invention What sive substance, a vulcanized rubber binder 15 5 I claim as new and desire to secure by Letters therefor, and chopped sponge incorporated Patent is v therein, said sponge constituting approxi 1. An abrasive wheel having pulverized mately one fifth of the bulk of the wheel. sponge incorporated therein. I This specification signed and witnessed 2. A grinding wheel comprising an abrathis eighth day of September, 1927. 10 sive substance in powdered form, chopped y sponge incorporated therewith, and a binder GILDEROY O. BURLEW. 

